Field of the Invention
Various embodiments of the present invention generally relate to a Virtual Local Area Network (VLAN), and in particular, to a Layer 2 (L2) Virtual Ethernet over an underlying Layer 3 (L3) IP network.
Description of the Related Art
VLAN is widely used in traditional customer private networks. VLAN is a widely used mechanism to handle and implement isolation and connectivity. Broadcasting can be performed within VLANs, while machines/Virtual Machines (VMs) belonging to different VLANs cannot communicate with each other. Traffic among switches can carry VLAN tags to implement connections between members in the same VLAN but connected to different switches.
As application environments of VLAN are expanding, conventional VLAN implementations (such as IEEE 802.1Q, etc.) face various challenges. When the configuration structure and application scenario of a VLAN change, for example, when customers migrate their VLANs into a Data Center Network (DCN), many requirements are imposed on VLAN implementations. These requirements are needed to guarantee the security, robustness and scalability of a VLAN. Furthermore, devices and apparatuses in a VLAN are also required to keep working in the same way as they usually do in their private network.
On the other hand, in a multi-tenant environment, each tenant needs to define its own VLAN, and since both physical nodes and VM instances are increasing, the number of VLANs is also increasing rapidly. Identifiers currently available for VLANs (VLAN IDs) can be insufficient. In a modern data center, at any moment quite a few VMs can be in a migration state and VM migration across the VLAN boundary needs many configuration changes in switches. Due to the deployment of multi-platform applications from numerous tenants, isolation and connectivity are key factors to be considered, because isolation ensures the security, robustness and scalability, while connectivity ensures the dynamic resource allocation and scheduling. However, current deployment schemes and technical applications for VLANs cannot satisfy the abovementioned requirements, and accordingly, are unable to provide desired services to more users in a larger-scale network environment.